This invention is directed to apparatus and an improved connection for securing an indicating element, or the like, to a cooperating shaft in fixedly held position against relative rotative as well as relative axial movement, and more particularly to a resilient bushing for attaching an instrument pointer to an indicating instrument.
Conventionally, pointers for use with instruments, such as an automobile speedometer, have been formed with openings which are designed to frictionally engage its supporting shaft. During installation, however, the amount of force required to press the pointer into place can damage both the supporting shaft and the speedometer. Friction fits can introduce torque, thereby inducing movement of the pointer from its zero position relative to the indicator. Resilient bushings, both split and non-split, have not provided a constant gripping force to obviate torques tending to disturb the position of the pointer relative to the zero position of its meter.
This invention overcomes the above problems by providing a pointer bushing which requires low insertion forces for installation. The bushing is secured at one end to the pointer and attaches to the supporting shaft by the action of a pair of cantilevered S-shaped spring elements integrally formed with the bushing, the outward end portion of the springs being biased radially inward and towards each other, and hence, into uniform gripping engagement against the shaft.
Advantageously, the pointer bushing requires less force to install, provides an axial shaft gripping engagement force that is generally constant over the shaft, and obviates rotative torques induced by resilient bushing portions that sometimes rotate the pointer from a desired zero position.
Other objects, advantages and features of the present invention will become apparent to one skilled in the art upon reading the following description and claims, taken in conjunction with the following drawings